Investigators have identified China as the origin of some nuclear weapons designs found in Libya last year, the Washington Post newspaper reported.

It said the international inquiry found that Chinese designs probably supplied to Pakistan in the 1980s were sold on to Libya by Pakistani-led smugglers.

It quoted officials as saying that some of Libya's documents were in Chinese.

The findings raise questions as to whether similar Chinese designs were supplied to Iran and North Korea.

These documents are very incriminating of China

David Albright, ex-UN arms inspector

Former UN arms inspector David Albright was quoted by the Washington Post as saying that Libya did not have a suitable missile to carry the weapon featured in the designs, but Iran and North Korea had more advanced rocket programmes.

Mr Albright later told the BBC's World Today programme that experts thought similar information "was offered to Iraq in 1990 - and Iraq just did not have a chance to pursue that deal because it was right before the Persian Gulf war started in January 1991".

"You have to almost conclude it went to Iran and... North Korea," Mr Albright said.

There has been no official reaction to the newspaper's report from China, which has long been thought to have provided Pakistan with nuclear technology until the 1980s.

The inquiry was launched after Libya's leader Colonel Gaddafi had decided to abandon the pursuit of the weapons of mass destruction and handed over the country's nuclear secrets to the US.

The blueprints had been analysed by experts from the US, Britain and the Vienna-based International Atomic Energy Agency, the newspaper said.